Layer modulating and electrical properties in acceptor-doped Sr5Nb5O17 ceramic with perovskite layer structure
Xiaoxu Duan , Jungu Xu , Xianfeng Yang , Xiaoling He , Cheng Wang , Laijun Liu
Microstructures ›› 2025, Vol. 5 ›› Issue (3) : 2025051
Layer modulating and electrical properties in acceptor-doped Sr5Nb5O17 ceramic with perovskite layer structure
Perovskite layer structured (PLS) oxides exhibit some novel physical properties, such as ultrahigh-temperature piezoelectricity, semiconductivity, and oxygen ionic transport. However, synthesizing 5-layer PLS oxides, such as Sr5Nb5O17 ceramics, using traditional solid-state reaction methods is challenging due to their low phase stability. In this study, we propose a new strategy to construct a 5-layer structure from a 4-layer structure. Specifically, Ga-doped Sr5Nb4.444Ga0.556O16.944 (5-SNGO), an iso-structural material to Sr5Nb5O17, was synthesized via a solid-phase reaction. The original design involved co-doping Ga and Mo at the Nb site of the 4-layer parent material Sr2Nb2O7 (4-SNO). However, it was found that only Ga was successfully incorporated into the structure, while Mo remained as SrMoO4, which was subsequently removed by washing with dilute sulfuric acid. X-ray diffraction, transmission electron microscopy, and second-harmonic generation analysis confirmed that the synthesized 5-SNGO ceramic exhibits a 5-layer structure with a noncentrosymmetric space group. The material demonstrated a frequency-independent dielectric permittivity of 60 above 1 kHz. Impedance spectroscopy revealed a very high resistivity of 1.95 × 105 Ω·cm at 900 °C, along with Debye-like dielectric relaxation exhibiting thermal activation behavior. This study presents a novel synthesis approach for constructing 5-layer PLS oxides from a 4-layer structure and provides insights into their structural evolution and electrical properties.
Perovskite layer structured / solid-phase reaction / Sr2Nb2O7 / Sr5Nb5O17 / ferroelectric properties
| [1] |
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| [2] |
|
| [3] |
|
| [4] |
|
| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
|
| [20] |
|
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
| [32] |
|
| [33] |
|
| [34] |
|
| [35] |
|
| [36] |
|
| [37] |
|
| [38] |
|
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